Brake holder for a floating-caliper disk brake with a brake pad guide spring

ABSTRACT

The present invention relates to a brake holder of a floating-caliper disc brake for motor vehicles at which brake pads arranged on either side of an associated brake disc are displaceably mounted. To ensure ease of displaceability a brake pad guide spring is provided that extends between the brake holder and the brake pads. For ease of mountability of both the brake pads and the brake pad guide spring, it is arranged for that the brake pad guide spring is mountable on the brake holder in a generally radial direction and is locked at the brake holder in both radial and axial directions by means of at least one fixing clamp, and at least one spring arm is designed at the brake pad guide spring and fixes at least one brake pad under spring bias in position on the brake holder in a clearance-free manner. These provisions not only improve the mountability of a brake of this type but also the rattle-free resilient arrangement of the brake pads.

TECHNICAL FIELD

The present invention relates to a brake holder of a floating-caliperdisc brake for motor vehicles at which brake pads arranged on eitherside of an associated brake disc are displaceably mounted. To ensureease of displaceability a brake pad guide spring is provided thatextends between the brake holder and the brake pads.

BACKGROUND OF THE INVENTION

DE 100 50 013 A1 discloses a disc brake of this type comprising a brakeholder fixed to the vehicle. In this application, the brake pads areguided in the brake holder in an axially displaceable manner, and aslide spring element is placed between the brake holder and the brakepads for greater ease of displaceability, through which element at leastone brake pad is locked radially at the brake holder. The sliding springelement is attached to the brake holder so as to be held captive in aradial direction. The geometrical shape of the slide spring element isadapted to a guide profile in the brake holder that is also used for thedisplaceable accommodation of the brake pads. The result is a form-fitattachment of the slide spring element on the brake holder. Such aform-fit connection of slide spring element and brake holder implies,however, a poor or complicated mountability of the slide spring elementon the brake holder. In addition, the simultaneous resilient arrangementof the brake pad by means of the slide spring element is insufficient sothat a principally rattle-free guiding of the brake pads cannot besafeguarded.

Based on the above, an object of the invention is to devise a genericbrake holder with a corresponding brake pad guide spring, the brakeholder facilitating the assembly of the individual components andadditionally enabling a comfortable resilient arrangement of anassociated brake pad in the brake holder by means of the brake pad guidespring.

BRIEF SUMMARY OF THE INVENTION

This object is achieved by a brake holder of a floating-caliper discbrake for motor vehicles comprising a corresponding brake pad guidespring. The brake holder comprises axially extending holder arms atwhich associated brake pads are displaceably arranged, said brake padsbeing arranged on either side of a brake disc and mountable in the brakeholder in a radial direction. For ease of displaceability of the brakepads in the brake holder, at least one brake pad guide spring isprovided, which is arranged between the brake holder and the brake pads.In a novel manner, the brake pad guide spring is mountable on the brakeholder in a generally radial direction and locked at the brake holder inboth radial and axial directions by means of at least one fixing clamp.To this end, the brake pad guide spring is simply shifted into acorresponding portion of the brake holder which is simultaneouslyprovided for the displaceable brake pad guide, with at least one fixingclamp becoming locked at the brake holder. The locking engagement bymeans of the fixing clamp is used to fix the brake pad guide springsafely on the brake holder, although it is easy to mount. For theadditionally rattle-free brake pad guide, the brake pad guide springincludes at least one spring arm that fixes at least one brake pad underspring load relative to the brake holder in a clearance-free manner.

A favorable embodiment of the brake holder with brake pad guide springis achieved in that the fixing clamp is locked at a correspondinglyconfigured radial undercut of the brake holder. Such an undercut ispreferably designed within the guiding portion of the brake pads on thebrake holder. This allows shaping the undercut while machining theguiding portion for the brake pads what is anyway necessary. Inaddition, it is expedient to provide axially effective fixing clamps.This allows fixing the locked brake pad guide spring at the brake holderboth in radial and axial directions. To further improve the attachmentof the brake pad guide spring it can be suitable to make the lockingengagement non-detachable so that the brake pad guide spring, after itslocking engagement, cannot be removed from the brake holder withoutbeing destroyed. An alternative attachment of the brake pad guide springis carried out by way of an appropriate projection on the brake holderat which the fixing clamp is locked, or which the fixing clamp embraces.Depending on the case of application, this arrangement allows attachingthe brake pad guide spring by means of one single fixing clamp in axialand radial directions.

In a preferred variant of the brake holder with a brake pad guidespring, the brake pad guide spring includes a first portion for radiallocking engagement of the brake pad at the spring arm, said portionforming a radial stop for the mounted brake pad. After the radialmounting of the brake pad in the brake holder with brake pad guidespring, the brake pad is thus prevented from lifting radially out of theguiding portion of the brake holder.

To facilitate the design of a rattle-free overall arrangement of thefloating-caliper disc brake, it can be provided that the brake pad guidespring locked at the brake holder abuts in a clearance-free manner atleast on guiding surfaces of the brake holder that are used for thedisplaceable arrangement of the brake pads on the brake holder.

Another advantageous variant of a brake pad guide spring is achieved inthat a mounting ramp is provided at the spring arm for facilitatingradial mounting of the brake pads. This simplifies the radialintroduction of the brake pads into the brake holder, thereby preventingthe brake pads from jamming in the brake holder.

In a suitable development of the brake holder with brake pad guidespring, the spring arm bears under preload against an inclined abutmentsurface of the brake pad, when the brake pad is mounted, and thus clampsthe brake pad with respect to the brake holder in a clearance-freemanner. This allows reliably preventing the undesirable development ofrattle noises. It proves favorable in this context to provide atangentially active stop for the spring arm subsequent to the inclinedabutment surface on the brake pad. Said stop is used as a tangentialabutment for the spring arm. Thus, the action of the spring arm allowsthe brake pad to be clamped in a rattle-free manner with respect to thebrake holder both in radial and tangential directions.

In another favorable embodiment of the brake holder with brake pad guidespring, the first portion of the spring arm, which abuts on the brakepad in the mounted condition, is configured as a slope with respect tothe axial direction. In particular, the preloading force of the springarm is variable in dependence on the axial position of the brake pad atthe slope, with the brake pad mounted.

The preloading force of the spring arm with slope thus varies independence on the displacement travel of the brake pad in the brakeholder. Hence, a force component directed axially to the brake padresults by means of the slope. Said force component can be used for theclearance adjustment between the brake pad and an associated brake disc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a-1 c show three views of a brake holder with a brake pad guidespring for the brake pads in a first embodiment.

FIGS. 2 a-2 b show two views of the brake pad guide spring of FIG. 1.

FIGS. 3 a-3 b show two views of a brake holder and an associated brakepad guide spring in a second embodiment.

FIGS. 4 a-4 b show two views of a brake holder and an associated brakepad guide spring in a third embodiment.

FIG. 5 is a partial view of a brake holder with an associated brake padguide spring in a fourth embodiment.

FIG. 6 is a partial view of a brake holder with an associated brake padguide spring in a fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The brake holder 1 shown in the Figures is a component part of afloating-caliper disc brake frequently used in motor vehicles. Brakeholder 1 is fixed to the vehicle, for example, by way of threaded boresor through-bores 2. On the other hand, it is also feasible to integratethe brake holder 1 into a component fixed to the vehicle such as thesteering knuckle. The brake holder 1 is used for the slidable support ofa floating caliper (not shown), on the one hand, and for an axially 3slidable accommodation of the brake pads 6, on the other hand, saidbrake pads being arranged on either side of the associated brake disc.In this arrangement, the floating caliper straddles the brake disc andthe brake pads 6.

To accommodate the brake pads 6, the brake holder 1 comprises holderarms 7 straddling axially 3 the radially outwards edge of the brake disc(not shown). In this respect the designations of directions used in thedescription of the Figures, e.g. axial 3, tangential 4, and radial 5,refer to the axis of rotation of the brake disc. Several guidingsurfaces 8 to 10 allowing a displaceable guide of the brake pads 6 aredesigned at the holder arms 7. To this end, lateral guiding portions 11of the brake pads 6 engage, mainly in a form-fit manner, into theguiding recess 12 in the holder arms 7, said recess being formed of theguiding surfaces 8 to 10. Thus, the abutment of the guiding portions 11on the guiding surfaces 8 to 10 allows transmitting circumferentialbrake forces that develop into the brake holder 1. The design of theL-shaped guiding portions 11 on the brake pad 6 and of the associatedguiding surfaces 8 to 10 further allows a uniform support of thecircumferential brake forces on the two holder arms 7.

To enhance the ease of motion of the brake pad guide within the holderarms 7, there is provision of a brake pad guide spring 20, which extendsbetween the brake holder 1 or the guiding surfaces 8 to 10,respectively, and the brake pad 6 in a first embodiment according toFIGS. 1 to 2. A brake pad guide spring 20 of this type prevents thedirect contact between brake pad 6 and brake holder 1 and facilitatesthe displaceability of the brake pad 6 by corresponding surfaceconditions of the brake pad guide spring 20. To this end, the brake padguide spring 20 is preferably made of a sheet-metal blank, e.g. ofspring steel, or any other material exhibiting good sliding propertiesat least on its surface. In addition, the brake pad guide spring 20 hasa resilient effect towards the brake pad 6 so that the brake pad 6 isretained on the brake holder 1 in a rattle-free manner.

The brake pad guide spring 20 comprises a base portion 21, which, onboth sides thereof, passes over into a guiding portion 22, and alsocomprises a spring arm 26. The guiding portion 22 is provided withcontact surfaces 23 to 25 for the abutment of the associated brake pad6, said contact surfaces ensuring an easily movable displacement of thebrake pad 6 with respect to the brake holder 1. Spring arm 26 serves forthe radial locking engagement of the brake pad 6 on the brake holder 1and additionally brings about rattle-free clamping of the brake pad inrelation to the brake holder 1. To this end, the brake pad guide spring20 is held captive on the holder arm 7. This attachment is carried outby means of at least one fixing clamp 27, 28, 29 locking the brake padguide spring 20 on the brake holder 1. According to the first embodimentof the brake pad guide spring 20 according to FIGS. 1 to 2, the radially5 active fixing clamps 27, 28 in each case engage into an undercut 13,14 on the holder arm 7 or within the guiding recess 12. The fixingclamps 27, 28 themselves are deflected from the guiding portion 22 bysimple machining. Thus, the configuration of the fixing clamps 27, 28and the associated undercuts 13, 14 allows a particularly favorablemounting of the brake pad guide spring 20 on the brake holder 1. As thisoccurs, the brake pad guide spring 20 is shifted radially 5 into theguiding recess 12 on the holder arm 7 until the fixing clamps 27, 28catch the undercuts 13, 14. The fixing clamps 27, 28 consequently fixthe brake pad guide spring 20 radially in the holder arm 7, and theguiding portion 22 abuts on the guiding recess 12 in a clearance-freemanner at least in the area of the guiding surfaces 8 to 10. The guidingsurfaces 8 to 10 or the contact surfaces 23 to 25, respectively, areused for the abutment or support of the brake pads 6. The clearance-freeabutment of the brake pad guide spring 20 is achieved, among others,because the angle α enclosed between the contact surfaces 23, 24 at thebrake pad guide spring 20 is dimensioned insignificantly smaller thanthe angle β enclosed between the guiding surfaces 8, 9 at the holder arm7. Hence, the result is the clearance-free abutment when the brake padguide spring 20 is locked. As a whole, the locked fixing clamps 27, 28provide such a rigid connection that it is impossible to dismount thebrake pad guide spring 20 from the brake holder 1 without destroying it.The other fixing clamps 29 embrace the holder arm 7 axially 3 on bothsides and thereby bring about an axially defined positioning of thebrake pad guide spring 20 on the holder arm 7.

For the radially active locking engagement of at least one brake pad 6,a spring arm 26 is additionally designed at the brake pad guide spring20 and, by abutting on the brake pad 6, simultaneously clamps the brakepad with respect to the brake holder 1. According to FIGS. 1 to 2, onlyone single spring arm 26 is provided at the brake pad guide spring 20,acting only on one of the brake pads 6. Of course, designs of the brakepad guide spring 20 with two arms 26 that act on both brake pads 6 arepossible as well. More specifically, a first portion 16 is provided atthe spring arm 26 for the radial locking engagement of the brake pad 6,said first portion providing a radial stop 16 for the brake pad 6. Saidradial stop 16 is preferably configured in the form of an angled-off orrounded edge of the spring arm end portion. However, the spring arm 26not only causes radial locking engagement of the brake pad 6 on thebrake holder 1 but also the pad's rattle-free clamping with respect tothe brake holder 1. To this end, the first portion 16 of spring arm 26bears under spring load against an inclined abutment surface 17, on theone hand, and against a tangentially 4 active stop 41 on the brake pad6, on the other hand. A spring force component both in radial 5 andtangential 4 directions is achieved for the brake pad by the abutment ofthe spring arm 26. Said spring bias ensures a rattle-free arrangement ofthe brake pad 6 in radial and tangential directions.

The essentially V-shaped configuration of the spring arm 26 furtherbrings about an easy mountability of the brake pad 6. In thisarrangement, the brake pad 6 is shifted during the brake pad assemblyfrom radially outwards into the brake pad guide spring 20 locked in theholder arm 7 until the spring arm 26, with its first portion 16, willmove into abutment on the inclined abutment surface 17 or on thetangential stop 16, respectively. Further, mounting of the brake pad 6is additionally simplified by the provision of a mounting ramp 18 on thespring arm 26. Said mounting ramp 18 facilitates the radial insertion ofthe brake pad 6 and prevents it from being jammed.

Another spring force component that acts on the brake pad 6 is realizedby designing a slope 19 at the first portion 16 of the spring arm 26.Said slope 19 forms an angle relative to the axial direction 3 and abutson the brake pad 6 when readily mounted. In dependence on the axialposition of the brake pad 6 within the guiding portion 22, consequently,there is a variable force effect by means of the spring arm 26 on thebrake pad 6. This leads to an axially 3 directed spring force componenttending to urge the brake pad 6 away from the brake disc (not shown)when the disc brake is ready for work. Thus, the slope 19 can be usedduring braking operation for the better adjustment of the clearancebetween brake pad 6 and brake disc. As another alternative for realizingan axial spring force component by means of the slope 19, the spring arm26 can e.g. also be designed asymmetrically with respect to a planenormal to the axial direction 3.

FIG. 3 a-b shows in two views a brake holder 31 with an associated brakepad guide spring 30 in an alternative embodiment. As described already,the brake pad guide spring 30 includes a base portion 33 interconnectingtwo guiding portions 32 for the brake pad accommodation. In theirreadily mounted condition, said guiding portions 32 in turn are arrangedin the guiding recesses 12 of the holder arm 34. In contrast to thepreviously explained embodiment, the brake pad guide spring 30 accordingto FIG. 3 a-b includes two spring arms 36 which abut under bias on anassociated brake pad 6 in each case by way of a first portion 35 in theform of a radial stop. Thus, both brake pads 6 can be radially lockedand clamped in a rattle-free manner according to this design variant ofthe brake pad guide spring 30. Further, the two spring arms 36 have adifferent geometrical shape compared to the first embodiment of thebrake pad guide spring. In particular, the spring arms 36 have a longerand highly curved design. In general, the defined rating of the springarm 36 permits adjusting the desired spring bias force that acts on thebrake pad 6 within defined tolerances. Thus, the design of the springarm allows purposefully adjusting the spring's biasing force dependingon the case of application. Different configurations of the spring armare hence feasible under the invention. Only one single fixing clamp 37is provided for the easy-to-mount attachment of the brake pad guidespring 30 on the brake holder 31. Said fixing clamp 37 has at least oneopening 38 which, with the brake pad guide spring 30 locked, encloses acorrespondingly designed projection 39 at the holder arm 34 in asubstantially form-fit manner. Due to this arrangement the brake padguide spring 30 is fixed on the holder arm 34 in a radial and axialfashion and, nevertheless, can be mounted radially in a very easymanner.

Another alternative construction of a brake pad guide spring 40 can betaken from two views referring to FIG. 4 a-b. The brake pad guide spring40 includes for each of the associated brake pads 6 a correspondingguiding portion 42 and a spring arm 46. Two fixing clamps 47, 48embracing the holder arm 7 are provided to fasten the brake pad guidespring 40 on the brake holder 1 or the holder arm 7, respectively. Morespecifically, the fixing clamps 47, 48 abut under preload on the holderarm 7 in the area of the disc's passage at the holder, that means in aportion of the holder arm 7 projecting above the brake disc directlyradially outside or extending between the guiding recesses 12 at theholder arm. Thus, the two fixing clamps 47, 48 ensure both radial andaxial fixation of the brake pad guide spring 40 on the holder arm 7.Further, the use of fixing clamps 47, 48 of this type obviates the needfor an additional machining of the holder arm 7 for the purpose ofattachment of the brake pad guide spring 40.

FIGS. 5 to 6 show two further variants for the attachment of a brake padguide spring 50, 60 of the invention on a corresponding holder arm 7.Two fixing clamps 57, 58 or 67, 68, respectively, are provided by meansof which the brake pad guide spring 50, 60 is locked at the holder arm7. Thus, the fixing clamps 57, 58 or 67, 68, respectively, ensure ineach case radial and axial fixation of the brake pad guide spring 50, 60on the holder arm 7. According to FIG. 5 the fixing clamp 57 embracesthe holder arm 7 in an arcuate fashion in the area of the disc's passageat the holder so that the fixing clamp 57 encloses the holder arm 7 overalmost half its periphery. This provides a very good grip of the brakepad guide spring 50 on the holder arm 7, without additional mechanicaltreatment of the holder arm 7.

The variant of the brake pad guide spring 60 according to FIG. 6achieves the non-detachable attachment on the holder arm 7 because thefixing clamp 67 with its end portion is engaged in an associated pocket61 of the holder arm 7 in a generally form-fit manner. This allows alsoa precise positioning and reliable fixation on the holder arm 7.

1. A brake pad assembly comprising a brake pad and a guide spring forengagement with the brake pad, the brake pad including a main portionand a lateral guiding portion extending from the main portion, thelateral guiding portion including a stop surface located on a first sideof the lateral guiding portion and a radial extension located on asecond side of the lateral guiding portion, the second side beingradially opposite the first side, the guide spring comprising an endportion for engagement with the stop surface, the end portion comprisingan axial spring force component with a sloped edge that is sloped in theaxial and the radial direction such that the slope edge has a first endand a second end radially offset from the first end, the guide springfurther comprising a guiding channel having a depth for receiving theradial extension.
 2. The brake pad assembly of claim 1, wherein theguide spring comprises a cantilevered spring arm that terminatestangentially inwardly over the guiding channel.
 3. The brake padassembly of claim 2, wherein the spring arm comprises a pair of V-shapedhinge portions separated by an opening and a central ramp portionextending between the V-shaped hinge portions, the central ramp portionforming a sliding surface that bends radially toward the guiding channelto allow the lateral guiding portion to slide radially over the rampedsurface and into the guiding channel.
 4. The brake pad assembly of claim1, wherein the end portion of the guide spring comprises a contourededge for engagement with the stop surface.
 5. The brake pad assembly ofclaim 4, wherein the contoured edge comprises a convex edge.
 6. Thebrake pad assembly of claim 4, wherein the contoured edge comprises anangled-off edge.
 7. The brake pad assembly of claim 1, wherein the guidespring comprises an elongated base having a first end and a second end,and wherein the guiding channel comprises a first guiding channelsection extending from the first end of the base for receiving the brakepad, and a second guiding channel section on the second end of the base,the second guide channel section being separated from the first guidingchannel section by an opening.
 8. The brake pad assembly of claim 7,wherein the spring arm extends over the first guiding channel sectionbut not the second guide channel section.
 9. The brake pad assembly ofclaim 1 further comprising a contact surface adjacent the guidingchannel, wherein a section of the contact surface is partially cut toform a flexible fixing clamp.
 10. A brake pad assembly comprising abrake pad and a guide spring for engagement with the brake pad, thebrake pad including a main portion and a lateral guiding portionextending from the main portion, the lateral guiding portion including astop surface and a radial extension having three sides, the stop surfacelocated on a first side of the lateral guiding portion and the radialextension located on a second side of the lateral guiding portion, thesecond side being radially opposite the first side, the guide springcomprising an end portion having an axial spring force component with asloped edge that is sloped in the axial and the radial direction suchthat the sloped edge has a first end and a second end radially offsetfrom the first end, and the guide spring comprising a guiding channelhaving a depth for receiving the radial extension and surrounding thethree sides of the radial extension.
 11. The brake pad assembly of claim10, wherein the guide spring comprises a cantilevered spring arm thatterminates tangentially inwardly over the guiding channel.
 12. The brakepad assembly of claim 11, wherein the spring arm comprises a pair ofV-shaped hinge portions separated by an opening and a ramp potionextending between the V-shaped hinge portions.
 13. The brake padassembly of claim 10, wherein the lateral guiding portion comprises thestop surface, and the guide spring comprises a contoured edge forengagement with the stop surface.